1. Field of the Invention
The present invention relates to an optical transmitter receiver module provided with a current regulating circuit to generate control current and a temperature controller to control the temperature of a light emitting or receiving element according to the control current, moreover, pertaining to an apparatus provided with the module.
2. Description of the Prior Art
The arrangement of the conventional optical transmitter module is shown in FIG. 7 of the accompanying drawings, which module comprises a light emitting element 10, a signal processing circuit 20, a temperature detector 30, a temperature controlling circuit 40, a temperature controller 50 and a voltage regulating circuit 90. This module generates a light signal in such a manner that an electrical signal output by the signal processing circuit 20 is input to the light emitting element 10. In the meantime, in order to feed power into the processing circuit 20 according to the predetermined operating voltage, the power voltage of the optical transmitter module is subject to step-down transformation by the voltage regulating circuit 90.
Further, such module as mentioned above is disclosed in the laid open patent JP-A No. H11-163462, for instance, wherein the temperature of the light emitting element 10 is kept constant against the change of the ambient temperature by the temperature control feed-back loop comprising the temperature detector 30, the temperature controlling circuit 40 and the temperature controller 50.
However, the problem with such conventional module as above is that the provision of the feed-back loop increases power consumption. As the power consumption increases, the optical transmitter module is internally overheated, so that at the high-temperature ambient its operating temperature goes beyond the maximum rated temperature, with the result that there is the risk of the signal processing circuit 20, the temperature control feed-back loop and the light emitting element 10 malfunctioning.
Thus, the present invention is to provide an optical transmission module and an apparatus provided with the module, which reduce power consumption and extend the operating temperature range.